Downhill skiing imposes substantial shock, impact and vibration upon the skier's legs as terrain is traversed. Such impacts and vibration often injure the skier's leg and knee joints, and such injuries limit the duration of a skier's enjoyment of the sport.
Various accessories and attachment for skis have been proposed which would absorb shocks and impact occurring during skiing and typical devices of this nature are shown in U.S. Pat. Nos. 2,330,731; 2,350,130; 3,917,298; and 4,139,214. However, prior art devices capable of absorbing vibration and impact during skiing do not provide the necessary stabilization and "feel" required by the skier during maneuvers, and ski suspension devices have not come into popular use.
Known ski suspension devices have utilized springs and air cushions for absorbing shocks and vibration imposed on the ski, but existing ski suspensions have not been capable of effectively absorbing such forces while also providing effective ski control, particularly with respect to the regulating of the desired forces to the lateral edges of the skis during maneuvering.
It is an object of the invention to provide a suspension for skis which is of concise configuration, capable of absorbing and damping vibration and impact imposed on the ski without transfer to the skier's legs, and which does not adversely interfere with the control of the ski.
An additional object of the invention is to provide a ski suspension which is relatively economical to manufacture, stabilizes the ski and improves tracking during turns.
An additional object of the invention is to provide a ski suspension which effectively absorbs and damps vibration and yet permits lateral forces applied to the suspension by the skier to be effectively transmitted to the ski edges.
In the practice of the invention the ski suspension comprises an assembly which is attached to the upper surface of a conventional downhill snow ski at the center of the ski at the location at which the bindings are normally attached. The suspension assembly includes a pair of upper and lower plates normally maintained in spaced parallel relationship, the lower plate being affixed to the ski, and the upper plate having the binding attached thereto.
The upper and lower plates have a plurality of compression springs interposed therebetween for absorbing the vibrations imposed on the ski and lower plate during use, the springs preventing the shock forces and vibrations from being transmitted to the upper plate. Posts are interposed between the plates to aid plate alignment and the posts and upper plate are relatively moveable to prevent the posts from interfering with the shock absorbing action.
A plurality of links or hinges are interposed between the upper and lower plates which permit the plates to move relative to each other in a vertical direction, but maintain a predetermined lateral orientation whereby the skier's weight can be effectively transferred to the ski edges as is necessary during maneuvering. The links include a pivot operative about an axis fixed with respect to the lower plate, and an upper pivot axis adjacent the upper plate is relatively displaceable with respect to the upper plate in the direction of the length of the upper plate parallel to the lateral edges of the plates and ski. This mounting of the links prevents interference of the hinges with respect to the relative vertical movement of the plates while permitting lateral forces imposed upon the upper plate by the skier to be directly transferred to the lower plate and the ski edges.
A compressible elastic foam material is also located between the plates having a plurality of voids or chambers defined therein. The chambers receive the compression springs, posts and hinges and the foam material functions as a gasket to protect these components from direct contact with snow and moisture, and simultaneously, the foam material functions as a shock absorber and damper between the plates which does not interfere with the shock absorbing aspects of the suspension, but provides improved "feel" and control during relative plate movement.
The aforedescribed relationships of components results in a ski suspension capable of effectively reducing shock and vibration which would otherwise be directly imposed upon the skier's legs and joints, and the suspension reduces leg fatigue and joint and back strain. The ski suspension stabilizes the ski reducing the effort normally exerted by leg muscles for turning and maintaining balance, and a smoother and firmer ride results, tracking is improved during turning for improving maneuverability and speed, and as fewer vibrations and impacts are transmitted to the bindings fewer occurrences of inadvertent binding release result.